Rudder



i Patented Oct. 7, 1930 Y i i i Y i i i Y i i UMT11D?Srrffs- PATENTTOFPICE f eno'nefnfnnsrrs oonoonlin, orrnvvnnncnf :Navitronic numana j Application fnedfseptemtr- 11, 1929. serial Natalee?.

This-invention relates to r'udders. 1 ficient steering in combination with the pro- Among the objects, of'thejpresent invcnpeller `12. "The invention, however, is not tion `is toprovide'an improved shiprudder confined to` the specificA type of ship here which is adaptedto impart'directional move.- sho\vn,jit being readily seenthatthe rudder V5. ment to `the ship through the rotation may be `mounted atj otherfportions oiwthe o5 thereof. f y ship"as, forinstance, the bovv,"and thedevce It is ai further object of the present invenmay i be used in nconjunction -With plural tionto provideanovel` and improved rudl propellerships `Withoutdepartimg from. the 1 j der which will a'ctttosteer a ship byskin fricspirit or scope of the inventionl j i V1.0 tion thereof, thev arrangement beingsuchthat The rudder of the present 1 invention in-` 60.V

the rotationfof thei'rudderl will effect a pres cludesa body 1a' mounted upon `a suitable op i ,sure .upon l the rudder `at right angles to .the erating shaft 15, the lower extremity of which path` or" the ship in adirection controlled by is mounted within a bearingl carried by the direction of rotation oftherudder,M i an extension 17 on the keel.` For rotating the l A still further objectof the presentinven shaft 15 and the body Many desired mecha- @5L tionisto Iprovidearotary rudder ofitapered nism may be provided, the present form of construction which `Will' provide Vincreased the invention using anelectric'motoni `The skin rictionsurface and which will present electrcmotorj 18 is mounted upon asuitable minimum" resistance to the Water crossed base 19 carriedonthesternof the ship; `'Ihis 20 rearwardly `by the propeller; form` of drive provides for electric control70 Another important object of the present oftheship romaremote steering point. The

'. invention is' to provide in'a rudder of the type body14 of therudder is,f as illustrated, of

described, a plurality of skin friction inangular cross section. In the preferred erni f creasing elements which will act to materialbodment of the invention thedevice is` pref-` i ly increase the efficiency of the device. erably rectangular in verticallcross section. 75 j L A further object of the present invention The device is of round horizontal crosssecf is to providein a rotary rudder, a plurality tion" throughout, thus `resembling a'pairof of spiral grooves, spiraling in opposite diconesjoined at theirbase. l i rections to increase resistance of the `device i As seen in tliedrawings, the rudderispro- ,j on one side as itrotates and to decrease revided With a plurality of threadlilre grooves B0 i Y sistance-on the opposite side. 20thefupper conical face ofthe rudde1""hav` A Numerous other objects of the present iningthe grooves, in oppositepitch asseen in vention Will be apparentfrom a consideraside elevation in Fig. 1 from thoseeofi the tion of the specification taken in conjunction lower conical surface, Wherebyon eachfside ,35 i with the accompanying drawings, in which the groovescdoperate to either-increase or S l v Figure 1 is aside elevation of a ship"em decrea'sethe skin friction-in accordancevvith bodying one `form of thepresent invention, `the direction ofrotationgoi the rudder. Tlus,

and j as shown in Fig.` 2, if therudder is turning Fig. 2 is a detail enlarged top plan view 1n clockwise-direction, thegrooves act.toi1`1 40 thereof. crease the. frictionon the` upper sideof? the 90 Referring moreparticularly to the draW- rudder as shownin this, ligure, -While Fdeings, a ship of conventional design has been creasing the `resistance on the .opposite side, indicated by the numeral 10, Figurev 1, and thus ,assisting the operation of the `rudder includes the usual keel 11 from which extends in steering: the ship. j It is `also `Within the i V a propeller 12.` The stern of the ship, as is scope oi the `present invention to provide 95 common practice, extends rearvvardlyover other equivalent means` for increasinggvthe L thepropeller, as at 13. friction. `'Ilherudderl `body may besuitab-ly In connection with the present invention it corrugated f or provided With projections will be understood that the rudder is oi'pareither spiral or straight which vou-ldifini 5U ticular coniiguraton for providing most efcrease the rictionot the rudder, the injnen` ,1001

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tion not beingl confined to spiral grooves which increase the resistance on one side while decreasing it on the opposite side. This, however, as illustrated, being a preferred embodiment of the invention.

In operation it is assumed that the maximum cross section of the device is in alignment with the axis of the propeller, and that the device tapers toward its upper and lower ends so that the minimum resistance is provided behind the central portion'of the 'propeller blades, while maximum effective surface is provided in direct alignment with the propeller axis.

In marine propulsion it has been found that the rear draft of water is at its maximum intermediate the ends of the propeller.

blades, and that at the axis of the propeller no effective rear draft is experienced. The device thus utilizes the actual ineffective area behind the propeller to accommodate the bulk of the propeller. The angular conguration of the propeller further provides for a maximum skin friction area with minimum displacement by the propeller.

It will be understood that in the operation' of the device, With a ship moving forwardly water passes evenly over the rudder when the propeller is at rest. If, however, the rudder is rotated a greater amount t of water will be carried upon one side of the rudder due to slin friction thereon. rIhe opposite side of the rudder which moves in the opposite direction to the Water, and which will due to skin friction with the water build up a pressure, thus exerts pressure on the stern of the ship in an opposite direction, wherebythe ship may be readily steered without the use of the flat type of rudder, the operation of which reduces the eficiency of a ship due to resistance effected when the rudder is turned at an angle with respect to the axis of the ship.

In the use of the present invention it is also possible to turn the ship without the usually required forward or rearward movement ofthe ship. It will be seen that with the propeller in stationary position rotation of the body 14 will act as a propeller for the ship moving the stern of the ship in'sidewise direction. Thus in maneuvering a ship provided with the present invention, it will not be necessary to accompany the turning of the ship with forward movement as is necessary in the conventional rudder-steering vessel.

From the foregoing it will readily be seen that the invention provides a novel, simple and improved rudder of high efliciency.

It will further be understood that the invention is not particularly confined to the angularity in the vertical cross section of the rudder as specified, but that such angularity may be controlled in accordance with the design of the ship.

It is understood that such changes in the design of the rudder Will not depart from the spirit or scope of the invention as outlined in the appended claims.

What is claimed is:

l. A rotary rudder for ships, including a double conical body having oppositelypitched spiral friction-increasing grooves on each conical surface.

V 2. A rotary rudder for ships, including a double `conical body having oppositelypitched spiral friction-'increasing grooves on each conical surface, the pitch of the grooves on one conical surface being opposite to the pitch of the grooves on the other conical surace.

3. In combination with a ship lia-ving a rudder, a rotary propeller associated with said rudder, said rudder being of maximum width in a horizontal plane intersected by the axis of said propeller, said rudder tapering in cross section from its portion of greatest width to its ends, the vertical cross section of the rudder being rectangular, the upper and lower surfaces of said rudder including independent sets of friction-increasing grooves.

4. In combination with a ship having a rudder, a rotary propeller associated with said rudder, said rudder being of maximum width in a horizontal plane intersected by the axis of said propeller, said rudder tapering in cross section from its portion of greatest Width to itsends, the vertical cross section of the rudderbeing rectangular, the upper and lower surfaces of said rudder including independent sets of friction-increasing grooves, the sets of grooves being spiral', the pitch of one set being oposite to the pitch of the other set.

GEORGE EUSTIS CORCORAN. 

